“It came back positive,” Bolsonaro said, donning a mask.
Bolsonaro , 65, took a test on Monday after experiencing symptoms of Covid-19, including fever.
His diagnosis comes three days after he had lunch at home of the US ambassador to Brazil Todd Chapman in capital Brasilia.
Earlier, his office had issued a statement saying he was in good health after he underwent a lung scan.
“I’m well, normal. I even want to take a walk around here, but I can’t due to medical recommendation,” Bolsonaro said.
Bolsonaro has repeatedly played down the impact of the virus, and has been seen in public neither wearing a mask nor adhering to social distancing norms.
Brazil is the second worst-hit country, with over 1.6 million cases of the novel coronavirus and 65,000 deaths.